#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <windows.h>
#pragma comment(lib, "Ws2_32.lib")
void main() {
  WSADATA wsaData;
  SOCKET RecvSocket;
  sockaddr_in RecvAddr;
  int Port = 27015;
  char RecvBuf;
  int  BufLen = 1024;
  sockaddr_in SenderAddr;
  int SenderAddrSize = sizeof(SenderAddr);
  //-----------------------------------------------
  // Initialize Winsock
  WSAStartup(MAKEWORD(2,2), &wsaData);
  //-----------------------------------------------
  // Create a receiver socket to receive datagrams
  RecvSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  //-----------------------------------------------
  // Bind the socket to any address and the specified port.
  RecvAddr.sin_family = AF_INET;
  RecvAddr.sin_port = htons(Port);
  RecvAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  bind(RecvSocket, (SOCKADDR *) &RecvAddr, sizeof(RecvAddr));
  //-----------------------------------------------
  // Call the recvfrom function to receive datagrams
  // on the bound socket.
  printf("Receiving datagrams...\n");
  recvfrom(RecvSocket, 
    RecvBuf, 
    BufLen, 
    0, 
    (SOCKADDR *)&SenderAddr, 
    &SenderAddrSize);
  //-----------------------------------------------
  // Close the socket when finished receiving datagrams
  printf("Finished receiving. Closing socket.\n");
  closesocket(RecvSocket);
  //-----------------------------------------------
  // Clean up and exit.
  printf("Exiting.\n");
  WSACleanup();
  return;
}

#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <windows.h>
#pragma comment(lib, "Ws2_32.lib")
void main() {
  
  WSADATA wsaData;
  SOCKET SendSocket;
  sockaddr_in RecvAddr;
  int Port = 27015;
	
  char* SendBuf = "Hello";
  int BufLen = strlen(SendBuf);
  //---------------------------------------------
  // Initialize Winsock
  WSAStartup(MAKEWORD(2,2), &wsaData);
  //---------------------------------------------
  // Create a socket for sending data
  SendSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  //---------------------------------------------
  // Set up the RecvAddr structure with the IP address of
  // the receiver and the specified port number.
  RecvAddr.sin_family = AF_INET;
  RecvAddr.sin_port = htons(Port);
  RecvAddr.sin_addr.s_addr = inet_addr("10.0.0.2");
  //---------------------------------------------
  // Send a datagram to the receiver
  printf("Sending a datagram to the receiver...\n");
  int sent = sendto(SendSocket, 
    SendBuf, 
    BufLen, 
    0, 
    (SOCKADDR *) &RecvAddr, 
    sizeof(RecvAddr));
  printf("Total %d bytes sent.\n",sent);
  //---------------------------------------------
  // When the application is finished sending, close the socket.
  printf("Finished sending. Closing socket.\n");
  closesocket(SendSocket);
  //---------------------------------------------
  // Clean up and quit.
  printf("Exiting.\n");
  WSACleanup();
  return;
}